title: Synergistic activities of fortimicin A and beta-lactam antibiotics against Pseudomonas aeruginosa.
abstract: The inhibitory and bactericidal activities of fortimicin A (FTM-A) alone against Pseudomonas aeruginosa were compared with those of FTM-A in combination with beta-lactam antibiotics. As tested by the checkerboard method, most beta-lactam antibiotics tested had synergistic effects on the inhibitory activity of FTM-A against one strain of P. aeruginosa. Addition of a sublethal concentration of carbenicillin resulted in a significant increase in the rate of bacterial killing of FTM-A against P. aeruginosa. The antibacterial activity of FTM-A against 50 gentamicin-susceptible and 50 gentamicin-resistant clinical isolates of P. aeruginosa was clearly enhanced by addition of a subinhibitory concentration of carbenicillin or piperacillin.
mesh_terms: D000617:Aminoglycosides / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002511:Cephalosporins / Q000494:pharmacology*; D004357:Drug Synergism; D010406:Penicillins / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000254:growth & development
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D010406:Penicillins; C023384:fortimicin A